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Last updated at 12:39 BST, Monday, 08 October 2012

Cleaning up space junk


5 October 2012

The International Space Station is to be moved into a different orbit to avoid the possibility of a collision with a piece of space junk. The station, which is currently home to six astronauts, will fire booster rockets to avoid a fragment travelling at around 28,000 kilometres per hour. It's estimated there are around 21,000 pieces of dangerous debris in low earth orbit.


Matt McGrath

International Space Station

International Space Station prepares to change orbit


Click to hear the report


Keeping an eye out for dangerous debris is a critical part of operating the international space station. A week ago, Russian controllers were ready to take evasive action when two pieces of junk loomed close. Further inspection indicated a move wasn't necessary at that point. This new threat is believed to be slightly more serious.

Controllers take a very few risks with the station - they move it if the chances of a collision are greater than one in 10,000. Earlier this year, astronauts had to take refuge in escape capsules, when a piece of debris from a satellite was detected too late to move the ISS. But the space junk missed by about 23 kilometres.

NASA tracks pieces of debris bigger than ten centimetres. Their numbers are estimated to have increased by 50 percent over the past five years, the result of a collision between two satellites in 2009. In 2007 China used a missile to destroy one of its own satellites and, in the process, created more than 3,000 trackable objects. For the six crew currently on board, the manoeuvre to avoid this piece of junk might provide a bit more excitement than recent activities, which have included mending a broken toilet.


Click to hear the vocabulary




take evasive action

move out of the way of something

loomed close

passed nearby



to take refuge

to hide for safety


man-made device which orbits the earth






planned movement